Alcohol consumption likely plays a pivotal, but largely ill-defined role in HIV infection, disease progression, comorbid conditions and adverse events from treatment (drug toxicity). This may be especially true among the nation's veterans. In preliminary work with HIV positive veterans, 33% report binge drinking, 21% report hazardous drinking and 32% have diagnosis of alcohol addiction or dependence. The Veterans Aging Cohort Study (VACS 5) is a five-site (Houston, New York, Bronx, Atlanta, and Los Angeles) observational study of veterans with and without HIV infection (n=4010). The study includes age/race/gender/site-matched veterans from general medical clinics to better differentiate effects of HIV and its treatment from those of comorbid conditions. Data sources include laboratory, pathology, pharmacy, diagnostic data, patient and provider surveys, and blood and plasma banking. Our long-range goal is to design, implement, and evaluate interventions that improve outcomes for people aging with HIV infection complicated by comorbid conditions including alcohol and other substance use, medical conditions, neuropsychiatric and cognitive disease, and homelessness. Targeted interventions for future studies include electronic medical record reminders and nurse-delivered brief motivational interventions. In order to be effective, these interventions require detailed information concerning specific health risks for individual patients. VACS 5 has received funding from the National Institute on Aging and the National Institute for Mental Health to conduct a 6-month feasibility study to begin August 2001 (VACS 5- Feasibility). These funds will allow us to complete half of our targeted enrollment and provide for no follow-up. Because of the substantial prevalence of alcohol use and abuse among our patients, we propose to extend VACS 5-Feasibility for 5 years to study the role of alcohol in determining patient outcomes in HIV infection. Specific aims address: 1) the influence of alcohol on adherence, CD4 cell count, viral load, Hepatitis C viral load, liver function, and complete blood counts; 2) the influence of alcohol on HIV disease progression and comorbid disease occurrence, symptom burden and quality of life, and survival and 3) provider and patient awareness and attitudes toward alcohol consumption. In addition to the standard data collection of VACS 5, a 30-day Time Line Follow Back will be self completed by all patients and validated by interview in a subset, and additional liver function tests will be analyzed on banked specimens (CDT, GGT, ALT, and AST). Four alcohol focus groups will be conducted at each site: 1) HIV positive patients who consume alcohol; 2) HIV negative patients who consume alcohol; 3) clinicians from HIV clinic; 4) clinicians from the general medical clinic. After completing baseline enrollment, follow up will occur at 6-month intervals and new patients will be enrolled as they present for care.